[BUG] KV two differend boltdb buckets in one storage

[SerafimArts]

I tried this code:

kv:
  first:
    driver: boltdb
    interval: 60
    permissions: 0777
    file: "rr.db"
    bucket: "A"

  second:
    driver: boltdb
    interval: 60
    permissions: 0777
    file: "rr.db"
    bucket: "B"

I expected to see this happen: All OK

Instead, this happened: Nothing (hangs on initialization)

The version of RR used: 2.3.0 (stable)

Errortrace, Backtrace or Panictrace

*empty*

[rustatian]

From the bbolt documentation (https://github.com/etcd-io/bbolt#opening-a-database):

Please note that Bolt obtains a file lock on the data file so multiple processes cannot open the same database at the same time. Opening an already open Bolt database will cause it to hang until the other process closes it. 

I can only expose some timeout to wait for the boltdb connection in the related configuration section.